Enhancement of renal excretion of zinc by hydrochlorothiazide

The effect of hydrochlorothiazide (50 mg twice a day orally for 5 days) on the metabolism of zinc was examined in four patients with idiopathic hypercalciuria, one with idiopathic osteoporosis, one with normocalciuric nephrolithiasis, one normal volunteer, and one with normocalcemic primary hyperparathyroidism. Urinary zinc progressively increased until the peak value, at approximately twice the mean of control values, was reached on the fifth day of treatment with hydrochlorothiazide. After treatment was stopped, it gradually decreased towards control values. Serum concentration of zinc increased slightly or did not change during treatment. In contrast, furosemide, triamterene, mercaptomerin, or oral "sodium loading" did not affect renal excretion of zinc.